Studio Technologies 55 2002 - Manual (Page 31)

Model 55/56 User Guide Issue 4, June 2002
Studio Technologies, Inc. Page 31
Power Amplifier Input Sensitivity
Optimum StudioComm performance is
obtained when the input sensitivity of the
control room power amplifier is adjusted
to match the Model 55’s output level. With
normal, but loud, listening levels you
should find the level potentiometer on the
Model 56 to be set to about 11 or 12
o’clock. If you find that you don’t have to
turn up the Model 56’s control that high,
reduce the input sensitivity of the power
amplifier. Most power amplifiers have
controls on their inputs to allow easy
adjustment of the input sensitivity.
Control Room Output Transient
Protection
Unique to the Model 55 Central Controller
is a power up/power down transient pro-
tection feature. It limits the chance of
damage to the control room loudspeakers
during the time when AC mains voltage is
connected, disconnected, or has signifi-
cantly changed from nominal. A combina-
tion of hardware and software is used to
monitor one of the power supply “rails.”
Until the rail voltage exceeds 81% of its
nominal value, an electromechanical relay
maintains a short circuit condition on the
control room output. After a one-second
delay the relay is released to function
normally. Whenever the rail voltage drops
below 79% of its nominal value, the relay
immediately goes to its mute state. During
testing it was found that upon power up
the control room output remained very
quiet; during power down a moderate
“tick” was the worst that was heard.